Heat Cramps (cont.)

Benjamin Wedro, MD, FACEP, FAAEM

Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences Center.

William C. Shiel Jr., MD, FACP, FACR

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

Who is at risk for heat cramps?

While heat cramps tend to affect those who are active in a hot environment, it
should be noted that heat cramps are one of the symptoms associated with heat
exhaustion as part of the spectrum of heat-related illness. Those individuals
who have impaired temperature control mechanisms are at higher risk for
developing heat-related illness. The body's most effective way of cooling itself
is through sweat, and then the sweat evaporates into the environment. Those at
most risk for heat cramps include:

Infants and young children because they depend upon others
to avoid the heat, dress them appropriately (avoid swaddling an infant since it
prevents air movement over the skin to promote sweat evaporation) and
provide enough fluid to drink

The elderly because they may have underlying medical conditions,
including heart and lung disease, and they can easily become dehydrated

People who live by themselves or who cannot afford air conditioning are
at higher risk for heat related illness

A variety of medications can impair the body's sweat and heat regulation.
Examples of drugs include medication prescribed for psychiatric conditions, including antipsychotic medications
and tranquilizers. Over-the-counter cold medications and antihistamines also
impair the body's temperature control mechanism.

What causes heat cramps?

While it was thought that dehydration and electrolyte imbalance was the cause
of muscle cramping, there are alternative theories as to why muscles cramp when
the body is exposed to heat.

Since heat cramps begin after significant exercise in a hot environment where
the affected individual begins sweating profusely, the theory was that muscles
were depleted of water and sodium affecting their ability to contract and relax.
Some new research suggests that as the muscles tire from excess activity and
work, the ability for the muscle to regulate its own contraction is lost and
this is called altered neuromuscular control. Regardless of the cause, the
diagnosis and treatment for heat cramps remain the same.